ACTIVATION OF CARBON-FIBERS BY NEGATIVE DC CORONA DISCHARGE AT AMBIENT-PRESSURE AND TEMPERATURE

After a suitable cleaning treatment, high modulus, unsized, polyacrylo nitrile-derived carbon fibres were surface-treated by negative d.c. co rona discharges under a flow of various nitrogen/oxygen mixtures at am bient pressure and temperature. The surface composition and morphology of the fibres, characterized before and after the treatment by X-ray photoelectron spectroscopy, X-ray excited Auger spectroscopy and scann ing electron microscopy, were influenced by several experimental param eters (applied potential gaseous atmosphere, time of treatment, geomet ry of the corona apparatus, post-treatment storage conditions, etc.). The matter is discussed in the light of previously published informati on.